Method and apparatus for cleaning articles, particularly metallic goods



April 25, 1933. K. J. R.- OBERTSON 1,905,968 METHOD AND APPARATUS FOR CLEANINGARTICLES, PARTICULARLY METALLIC GOODS Filed Aug. 25, 1928 ma /Wm M By Z7 Arman/7 Patented Apr. 25, 3933 KENNETH JAMES RENNIE ROBERTSON, OF

aeaaaea LONDON, ENGLAND, assrelvoa TO, enema ENGINEERING COMPANY LEIITED', OF LONDON, ENGLAND METHOD AND APPARATUS roe CLEANING narrows, raarrcutmv wrung I eoons Application filed August 25,1928, Serial No.

The main object of the present invention is to provide a method and apparatus for cleaning articles, more especially metal articles and castings, wherein the whole surface of the articles will be subjected to solvent action, preferably combined with a scrubbing or washing movement, and a second object is to provide a cleaning plant from which the articles emerge in a dry condition.

A further object is to provide for the continuous use of a comparatively small body of solvent by re-circulating the solvent through the cleaning plant and extracting any dissolved grease and dirt after its contact with the dirty articles, whereby a supply of clean vapour to the plant is obtained.

A still further object is to prevent losses of the highly volatile solvents employed by leakage to atmosphere and thereby render operation of plant according to the invention economical. a

In accordance with the present invention a method of cleaning greasy articles consists in immersing them in vapoursolvent for the grease while at a temperature below the condensation temperature of such vapour solvent, wherebythe vapour condenses on the articles dissolving the grease which falls oif in solution and thus warms the articles, leaving them dry.

To obtain continuous cleaning the articles are preferably traversed through a bath of the vapour solvent, the grease charged con-- densate of which is regenerated and resupplied to the bath as clean vapour after extraction of the grease, and the bath is thus mainlained charged with the clean vapour solvent necessary for efl'ective cleaning of the articles.

The solvents used are preferably those whose vapours are heavier than air and such as will readily remove grease, wax or oils from metallic goods without anv chemical efl'ect on those goods, and the employment of such vapours permits of an open trough or chamber being used, the vapour lying near the bottom of the trough or chamber. and to a predetermined height controlled by the admission of vapour, and if desired also by refrigerating inean's located in the upper zones of the trough'or chamber which cause RElSSU 302,038, aim in Great Britain June 13, 1928.

any vapour rising to their vicinity to condense and fall to the base of the chamber.

Preferred apparatus for cleaning greasy articles according to the invention, includes a bath of vapour solvent, a conveyor traversing articles through such bath, and regenerating stills extracting the grease charged condsensate from the bath, regenerating and maintaining the bath charged with clean vapour through inlets connecting the bath with the stills.

Preferably the inlets are disposed so as to produce a circulating movement of the vapour in the nature of a convection current, and in addition such inlets are preferably duplicated or multiplied, each set of inlets having an associated regenerating apparatus so that .one apparatus may be disconnected and cleaned by the ejection of accumulated grease anddirt, while the other supplies the bath with the regenerated clean vapour. v

At the bottom of the bath outlets are provided for collecting the condensation products and these outlets are connected to regenbath, that is to say, that thermostats may 1 be disposed just above the vapour bath so that when the Warm vapour reaches the thermostats the regeneration is cut down. Such an arrangement may be utilized 'in conjunction with the refrigerating zones aforesaid or alternative thereto.

The'invention will be further des'cribed with reference to the accompanying sheet of explanatory drawings which illustrate diagrammatically by way of example a preferred formof apparatus for carrying the invention into effect, and in which:

dependent on the form of the artide-may clmveyororsuspmdeddiredzthnefmnby meansofhoohs. Theartides larepreferahlyatnormalorroon Intheexampleillush'atedthemnveym2 if! inacounterdockwlse' dim the articles 1 about to be dulled at 6 aftnpamage through the (inning rule 7 the bath 1 cleansed as required by the rmoval of any gleam a dirt whidl adhered to their surfaces. 7

8 repesmts vapour inkt ranks in the m 7,, which are W in the vicinity of the feed emlveyll' 2 and the va pour-at a mwlntebvatndtmperatmev issuing frmn the inlets 8 impinges on the geasy articles 4 to he cleansed, which, due to their lower turpentine m unashamtinnofthevapour deamteafter thesalpafmialgmase and dirt carried by the artHes 4 falling to the bottom 9 of the bltlh 1 from whale it 10 and 11 and p as desired.

The vapour circuit is illustrated in Fig. 2anditwillbesemthatthew'astepipes 10 and 11 communicate with stills 12 and 13respectivelyinwhid1theeondenseda' pourisregeneratedbybeingboiledunder the influence of sourcs of but It and 15 in association with each ofthe stills 12 and 13, the regenerated vapour passing through conduits 16 and 17 and the bowls 8 to the cleaning zone 7 and the collected grease and dirt being discharged from the bottom of the stills 12 and13-say at intervalsthrough conduits 18 and 19 provided with suitable valves or taps adapted to regulate the discharge. 7

As has already been mentioned the vapours utilized in the bath' 1 are preferably those heavier than air, and such as will readily re move grease, wax or oils from metallic goods without having any chemical effect on the goods, but even with heavier than air. vapours, an excessive regeneration from the stills 12 and 13 taking place, a certain proportion of the vapour in the bath 1 would leak to atmosphere unless special provision were made for its prevention. Accordingly in the upper zones of the bath 1 a series of cooling pipes 20 are disposed around the inner surface of the bath 1 through which pipes refrigerant is preferably conveyed, so that on the vapour reaching the upper zones of the bath, that is in the vicinity of the cool a a pipelhthevapormpplypipe 17, andsim heat tothe sfill 13, thereby regeneratmnofthevapour disposedasuitablesourceofheatforexample,agasburner14 or15,thesupplyofgas towhich maybeunder control item the thermostat 23 by means of a diaphragm valve 25, and the sill being provided with a discharge conduit such as 18 or 19 for the collected grease and 4 In operation and using as 18 or the cleansing medium or solvent, say dichlorethylene having a boiling point in the neighbourhood of 125 F., the stills are arranged to deliver: the vapour through the inlets 8 at a temperature of say and the article to be cleaned possessing a normal temperature ofsay 60 F. are fed to the conveyor 2 at 5 mpply of heat to the.

and conveyed into the cleaning zone 7, where,

by reason of their relativecoldness, condensation of the solvent vapour is effected on their urfaces, whereby the grease and-dirt coating is dissolved ofl in solution whichas liquidfalls to the base 9" of thebathand passes through the waste pipes 10 and 11 to the stills 12 and 13 and the articles are dried by the heat from the condensing vapour.

Regeneration is effected in the stills under control of thethermostat 23, the regenerated 'stills l2 and 13 from whence vapour being supplied in' the cleaning zone 7 through the vapour inlets 8 and the residue grease and dirt remaining in the base of the y it is collected as required.

Where desired, the conveyor 2 may be arranged so that the articles 4 after cleaning are passed'through a chamber in which hot air is-circulated, in order to remove the last traces of solvent, or alternatively a separate conveyor may be'used for this purpose.

An alternative method of regenerating the vapour and simultaneously separating the collected grease and dirt is illustrated in the dotted lines in Fig. 1 wherein the base 9 of the bath 1are shown a series of heating pipes 26 through which may be passed steam or other media adapted to maintain the pipes at a temperature suflicient to effect vaporization of any condensed liquid'falling in their vicinity, such temperature depending on the particular vapour or solvent used, and being conveniently controlled by suitable thermostats.

It may be found preferableto arrange the series of refrigerant cooling pipes 20, so that, they are hingedly secured to permit of the opening of the bath to atmosphere at the en-' t 5 and the exit 6lbeing suitably regulated,

w ile although the apparatus shown includes two stills 12 and 13 for regenerating the .Vapour, more of these stills may be provided if desired, each preferably under thermostatic control, so that individual stills may be dismantled, or cleaned while theapparatus remainsinoperation.

The method of andapparatus forcleaning articles according to the invention assures completeremoval of all grease from-the articles, which, traversingthe vapour in a direcxtion at right angles to its movement, are

moved ina manner equivalent to agitating the articles in the vapour, complete, subjection-of the articles to the vapour being thus ensured.

By ensuring that the articlesentering the a bath are in-a relatively cold conditionwhile the vapour is at a moderately high tempera- .ture the heat liberated 'by the solvent condensing on the surfaces of the articles raisestheir temperature, thus softening any grease on their surfaces and rendering it more-easily;

soluble whilst evaporation of any condensed solvent is ensured prior to the articles leaving the bath so that they issue in a cleaned dry condition.

Further the vapour treatment according reused.

' to the invention permits of the vapour penetrating to the surface of the articles to be cleaned'priox to its condensation, thereby effecting an' exceptionally rigorous detergent effect with consequent complete removal of any grease and dirt from their surfaces.

Although the invention has been described I sisting ingenerating a vapor, collecting the vapor in a retainer open to the atmosphere,

*causing some of said vapor to condense on an object to be degreased by immersing the object within the'vapor and effecting surface condensation tordissolve the grease on the y object. t

3. A method of removing oil and grease from surfaces, consisting in immersing a surface to be degreased within a vapor bath open :to the atmosphere, providing a volume of vapor at a temperature greatly in excess of that-of the surface, producing speedy condensation of some of the. vapor on said surand, oil thereon, and maintaining a volume of vapor sufficient to completely cover the sur l face during the degreasing operation including the condensing step.

I 4. -A method of degreasing materials, consisting in collecting a volumeof vapor in an open container, immersing material to be degreased within the container, removingcondens ate from the container, and maintaining substantially a constant level of vapor within the container. a

5. A method of degreasing, consisting in collecting vapor in a container open to the atmosphere and condensing some of the vapor. on a surface to be degreased by 'plung ing the surface within the vapor, producing a volume of\ condensate suflicient to dissolve and wash the grease from the surface and face and causing absorption of'the grease using the condensate to provide additional vapor. 6 A object to be cleaned, consisting in generat-. ing vapor from a liquid solvent; collecting the vapor in a retainer open to the atmosphere to method ofremoving greasefrom an provide a definite volume thereof, immersing an object to be degreased within the vapor to cause condensation thereof on the object, collecting the condensed vapor and regenerating that portion of the condensate adapted to be 7. A method of degreasing surfaces and leaving them in substantially dry condition, consisting in immersing asurface within a &

vapor bath open to the atmosphere at a temperature below the condensation. tempera ture of the vapor in the bath, whereby the vapor will condense on the surface and raise the temperature of the surface.

8. The improved method of degreasing articles which consists in continuously heating a solvent above its point of vaporization and thereby causing it to ascend in a closure open to atmospheric pressure to an area cooled to a temperature below the dew point of the vaporized solvent thereby causing the same to descend and again be heated to maintain a space filled with a condensing solvent through which the articles are slowly passed.

9. A degreasing apparatus comprising a vapor chamber having inlet and outlet openings toward the top thereof, a grease solvent liquid tank, means for heating said tank to vaporize liquid solvent contained therein, a vapor conduit connecting said tank with said chamber, cooling coils arranged atthe upper part of said chamber for condensing the vapor therein, a drain pipe connecting said chamber with said tank. and a conveyor ar ranged to carry articles through said chamber and expose them to the condensing vaporous solvent.

10. A degreasing apparatus comprising a vapor chamber having ends upwardly in-- clined to form inlet and outlet passages,

vapor condensing coils arranged in said "of the trough,- said inlet and outlet being, arranged with respect to the body of the chamber at the ceiling thereof, a pair of grease solvent liquid tanks, means for heating either of said tanks, a vapor conduit con- 1 necting each of said tanks with said chamber, closure means in each of said conduits, a liquid drain from said chamber to each of said tanks, closure means in'each of said drains, and an endless chain conveyor arranged to pass along said chamber through the inlet and outlet opening passages.

11. A combination of apparatus for cleaning greasy articles comprising a trough having an inlet and anoutlet open to the atmosphere, cooling means in combination with the trough adjacent said inlet and outlet, the body of the trough being arranged at a level below said inlet and outlet, an endless conveyor entering the trough from a level above said inlet and adapted to convey arti-- solventvapors, means for feeding vapors from the still within the trough above the line of travel of the conveyor and means for removing grease and dirt from the bottom trough so that vapor heavier than air will be retained in the body of the trough, wholly covering the portion of the conveyor therewithin, and have its upper level below the inlet and outlet openings.

12. Apparatus for cleaning articles comprising a trough substantially U shaped in form, the body. of the trough bein the lowermostv portion of the U, means or vaporizing a liquid solvent, nozzles for discharging the vapor in the upper portion of the body of the trough,- means for returning grease laden solvent to said vaporizing means, means for Withdrawing grease and residue from the bottom of the body of the trough and returning the same to said vaporizing means and conveying. means traversing the body of the trough, said conveying means beingv adapted to carry articles to be degreased within the trough and remove them from the trough through aninlet and an outlet open to the atmosphere, coolingmeans for preventing escape of vapor from the trough to the outer atmosphere, and means for controlling the level of the vapor within the trough.

13. A combination of apparatus for degreasing articles comprising a trough, U shaped in form, an inlet to and an outlet from said trough open to the atmosphere, cooling means for preventing escape of vapor from the trough to the outer atmosphere, the body of the trough comprising the bottom portion of the U, means for evaporating a liquid solvent externally of said trough, a nozzle leading from said means to the upper portion of the body of the trou h, a drain from the bottom of the body of the trough leading to said means, and means for lowering articles within the trough and withdrawing them therefrom.

14. A combination of apparatus of the character described comprising a trough having an inlet and an outlet open to the atmos phere and at a level above the body of the trough means for producing solvent vapors externally of the trough, nozzles for feeding vapors from said means within and at the uppermost portion of the body of the trough, cooling means for preventing escape of vapors to the outer atmosphere and a conveyor for carrying articles to be degreased traversirlig the body of the trough beneath said nozz es.

" Y 15. A degreasing system having a trough at a certain level, an inlet to and an outlet from said trough open tothe atmosphere at a. level above the trough, means for generating solvent vapors and feeding it within the trough, means comprising condensing coils to confine the vapors within the trough and above the body thereofbut below the inlet and outlet means for returning used solvent to said vapor generating means, and means for conveying articles to be degreased within the trough. v c

16. A combination of apparatus of the character described comprising a trough having an inlet and an outlet, means for conveying articles within the trough and removing them therefrom, means comprising a still for generating a; vapor adapted to dissolve ease, means for feeding the vapor within 1; e trough, means for removing condensate and residue from the tron h to said still for regeneration, said trou having cooling means for preventing escape of vapor throu h said inlet or outlet, and means for retaimng'the level of the vaporbelow the inlet and outlet. p

17. A combination of apparatus of the character described having a trough, a vapor generator apart fromsaid trough,an arran ementof nozzles for feeding vapor from a generator to the upper portion of the trou h, means for withdrawing liquid and resi ue from the lower portion of the trough to the generator, one portionof the trou h adapted to be completely filled with vapor om top to bottom, the trough having an extension open to the atmosphere, cooling means for con- 2 fining the vapors to the trough and means for traversing articles to be degreased within the trough between the levels at which vapor is admltted and liquid and residue removed.

In testimony whereof I afiix my signature. KENNETH J AlES RENEE ROBERTSON.

@HTIFIGATE 0F 'iwf IQE;

4%25mn3 fie. 1,905,968. ipril 25, 198$.

Kenneth Jams Renxaia Bubertaom.

It is hareby cartified. that error appwm in tlm pr-intefi gpecification of the shave mmbemd patent mqmifiw comma 'rtion follows: In tha dming, Fig, 2, ehmm appmr am sham below instaad. of as shown in the pam mta mge 1 before line 1, insert the following pamgmph:

This invention relates to methodsand apparatus for vchamp in; articles, particularly metallic goods. I

Page 2, line 115, strike out the min'ber and. wo rd.'""18 02",

and line 120, fpr "article" read articlea; page 3,'-1ine' 82, claim-2, for ":Iigreaez'tng read "degreasing"; page 4;,

line 121, claim 15, after "outlet" insert a co and-. t'hat the said Letters atent should; be read with these corrections therein that the same may conform ,to' the record of them case in the Patent Office.

signed and. sealed this 30th day of May, LID- 1933.

- H.- 3- 'M00!'& (Seal) Acting Commissioner of Patents. 

